Firing device



Sept. 9, 1941. FERREL 2,255,245

FIRING DEVICE Filed April 26, 1958 H I &

J ATTORNEY Patented Sept. 9, 1941 UNITED STATES PATENT OFFICE Clyde B. Ferrel, San assis' or to Ferrel Inc., San Francisco, Calif., a

corporation of California Application April 26, 1933, Serial No. 204,358

, 1 Claim, (01. lot-as) This invention relates to a method and apparatus for firing or detonating projectiles at varying elevations or distances from a target or other object to be shelled or bombed.

Two methods are in general-use for setting ofi bombs, shells and the like. One method depends upon impact, or, in other words, when the bomb strikes its target, for instance, the roof of a building, the impact is depended upon to'detonate the bomb. The other method depends upon a time fuse or similar mechanism, and unless the range is definitely known and the timing accurate, the bomb may bury itself before the fuse fires,. in which case comparatively little damage is done.

Incendiary bombs, and bombs and shells loaded with shrapnel, are exceptionally destructive if fired or detonated at the proper moment. On,

.flight of the projectile.

sired.- Point fuses are usually employed in high explosive and chemical shells to obtain quick action and to burst the shell before it has pence 'trated the ground. Base fusesw are in general use in projectiles for penetrating hard substances such as armor plate, concrete, etc., where a point fuse would ci'ush and fail upon impact. Most pact. The time interval in most time fuses is the other hand, if detonation is too late the bomb or shell will bury itself in a field or building, and when itdoes explode or burst, the range of action is very much confined and of comparatively little value.

The object of the present invention is to provide a method,and apparatus for firing projectiles of varyingtypes; to provide a firing head in which the mechanism for firing the bomb is contained; to provide a firing or detonating mechanism which may be set to fire or detonate the bomb at the most eliective point or elevation above a target or object to be bombed; and, more specifically stated, to provide a firing head which is capable of projecting one or more beams of rays which'willbe reflected by the surface of the target when-the bomb or projectile is within a predetermined distance thereof, said reflected rays being directed against a photoelectric cell in the firing head to energize the same and permit the flow of an electric current therethrough, said current being adapted to be amplified suiiiciently to ignite the explosive in the shell.

The apparatus or mechanism employed is shown by way of illustration in the accompanying drawing in which- Fig. 1 is a longitudinal section of the firing head and the forward end of the projectile;

Fig. 2 is a cross-section taken on line I[Il of Fig. 1; and

Fig. 3 he cross-section taken on line III-III- 'of Fig. 1, with the members and 2| omitted.

Fuses are used in practicallyall service projectiles such as incendiary bombs, chemical bombs, shrapnel shells, etc., to detonate, ignite,

or the bursting charge of the projectile at the time and imder the circumstances deobtained by means of the burning of a powder train the length of which is varied by the setting of the fuse. Mechanical means are also employed for setting ofi the projectile or bomb.

Mechanical timers and burning fuses are dependable when the range is definitely known,

but when projectiles such as incendiary bombs,

or burning fuses or other timing mechanism is 7 not relied upon, I prefer to term my firing device a firing hea In the drawing, A indicates the firing head and B the forward portion of the projectile. The projectile will be loaded in a suitable manner with an explosiv charge such as indicated at 2,

and this will be separated from the head by 7 means of a disk or hcavygasket such as shown at a which is held against the seat or shoulder 4 by means of the inner end of the head. That 7 is, the head is provided with a reduced threaded portion 5 which is screwed into the forward end of the shell and which serves the purpose of securing the gasket 4 in place and also to secure the head on the forward end of the projectile. The firing head of the projectile is provided with a central axial opening 6 and one or more surrounding openings 1, the number of the sub rounding openings being shown in the present instance by three, as shown in Fig. 2.

Suitably secured within the central opening 6 is a sleeve 8 on the inner end of which are formed three cams generally indicated at 9, I and II. The sleeve is rotatable within the opening 6 and is also adapted to rotate a second sleeve I2 which is mounted in the interior thereof, this sleeve being keyed or splined to the sleeve 8 so that while it is rotatable in unison therewith, it may also be longitudinally movable. The forward end of the sleeve I2 carries a pair of lenses I4 and I5, and the inner end is internally threaded as indicated at I6.

Disposed rearwardly of the sleeves 8 and I2 is a cylindrical housing I1 which is externally threaded and which extends into the internally threaded sleeve I2. Mounted within the housing I1 is a photoelectric cell I8, and adapted to admit rays of light, or equivalent means to energize the cell, is a small opening I9 which is formed in the forward end of the housing I'I.

Disposed between the gasket 3 and the housing I! are two box-like housings 20 and 2|. The housing 2| contains a spark coil not shown, and the housing 20 contains one or more dry batteries and a current amplifying mechanism which is not shown. The spark coil is connected with two terminals 22 and 23 which extend through the asket 3 and terminate within the projectile; that is, their ends project directly into the explosive with which the projectile is loaded, and when the spark occurs in the space between the terminal ends, ignition and firing of the explosive will take place. This is accomplished as follows:

Pivotally supported as at 24 rearwardly of each of the openings 1 are tubular elongated housings '25 in the forward ends of which are mounted projecting or concentrating lenses 26, and in the rear ends of which are mounted electric bulbs or lamps 21. Each bulb is connected with the source of current supply, to-wit, the batteries contained in the housing 20, and so is the photoelectric cell I8, which is in turn connected with the amplifying mechanism and that in turn is connected with the spark coil 2 I.

A switch, generally indicated at 30, is interposed in the circuit between the batteries and, the-- several elements actuated thereby. The switch has two contacts, to-wit, the one indicated at 3| and the other indicated at 32. One wire 33 from the battery connects through means of a spring 34 with the contact 3|. The other wire from the battery 35 connects with the contact 32. When the contacts 3I and 32 are separated, the entire mechanism is dead, as the circuit between the several parts is broken. Hence, when the projectile, bomb or shell is mounted in the hangar of an airplane, the circuit should be broken and should only be closed at the time of firing or releasing the projectile. To accomplish this, a plunger 36 is employed. This is connected with the contact 3|, and when the projectile is mounted in the hangar of the airplane, it is pushed inwardly thereby so that the circuit is broken, but the moment the projectile is fired or released, the plunger becomes released and is forced outwardly by the spring 34, thus closing the circuit. When the circuit is closed, the bulbs 21 begin to glow and beams of light are thus projected by the several lenses 26.

Now if a target is placed in front of the projectile, these beams of light will be reflected, and assuch will enter the central opening 6 where they are concentrated by the lenses H and I5 and projected through the small opening I9 against the photoelectric'cell I8. When this occurs, the photoelectric cell becomes energized and current flows therethr'ough. This current is then amplified and flows to the spark coil 2| and produces a spark between the terminals 22 and 23 of sufficient intensity to ignite the explosive.

In actual practice, I prefer to project one or more beams of infra-red rays and to provide a photoelectric cell which is sensitive to these rays only. The ultra-red rays are projected during the flight of the projectile toward the target. The target may be a field where troops are marching, or it may be a building, etc- Whatever the target may be, rays will be reflected therefrom, and when the reflected rays enter the aperture 6, they will be concentrated by the lenses I4 and I5 and will impinge upon and energize the photoelectric cell.

By rotating the sleeve 8 and the cams 9, I0 and II formed thereon, the housings of the tubes 25 will swing about their pivots 24, and the angle of the projected beams may thus be varied. Hence, as the angle of incidence is equal to the angle of reflection when a projected beam of light or the like is considered, it becomes possible to fire the bomb at any elevation or distance from the target. For instance, the beam projecting tubes or housings 25 may be adjusted to such an angle that reflected rays will enter the aperture 6 when the projectile comes within one hundred feet of the target. The bomb will thus be fired within one hundred feet of the target. Again, the angle of the light projecting tubes or housings may be adjusted to an angle where the reflected rays will enter the aperture when the projectile is Within two hundred feet of the target, and so on. Thus it becomes possible to fire at any distance or elevation above the target,

and any chance of burying the projectile or firing it at too high an elevation is thereby avoided.

It has been previously stated that by rotating the sleeve 8 and the cams 9, I0 and I I formed or secured thereon, it was possible to adjust the angle of the projected beams. .At the same time, it is desirable to adjust the concentrating lenses I4 and I5 with relation to the photoelectric cell. It is for this reason that the threaded connection I6 is formed between the inner sleeve I2 and the housing I1. For instance, as the angle between the housings or tubes 25 and the longitudinal axis. of the aperture 6 increases, the lenses should be drawn toward the photoelectric cell in order to properly focus the reflected rays thereon. Conversely, as the angle decreases, the distance between the lenses and the photoelectric cell decreases. This adjustment is ordinarily attained by the mechanism shown.

While the infra-red --rays have been referred to, it is obvious that otherrays of the spectrum may be employed, but, whatever ray is employed, a screen or photoelectric cell sensitive to that type of ray should be employed, as other rays entering during flight must not have any efiect on the photoelectric cell.

A disk I'Ia, which is externally threaded, forms a base or support for the'housing I1, and it is screwed into or between lugs I'Ic formed within the head between the compartments la in which the beam projecting tubes 25 are mounted. The housings 20 and 2I may be secured directly to the disk or gasket 3 or to the lugs or partition members formed between the compartments la.

current flow for igniting the explosive charge in These and other features 01! the invention are merely suggestive'oi the structure, and changes may obviously be resorted to within the scope of the appended claim. Y

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

A firing deviceior a projectile, comprising a head secured to the trout end of the projectile, said head having a central longitudinally extending light-gathering passage formed therein, a photoelectric cell mounted in the light-gathering passage. and adapted to be energized by reflected lightrays, a source of electric current supp y when it is to cause a current flow through the cell,

energized, means actuated by said 15 the projectile, a light projector carried by the head and disposed at one side of the light- I gathering passage and on an angle thereto, said projectedlight being reflected by a target and said reflected light entering the light gathering passage to energize the photoelectric cell only when the projectile is within a predetermined dktance of the target, and means for adjusting the angle of the light projector with relation to the longitudinal axis of the light-gathering passage, so that the energization of the photoelectric cell may take place at any predetermined distance from the target.

CLYDE B. FERREL. 

